1. Those cons easily outweigh the pros

The Ryan budget is obviously the #1 point of attack - and rightfully so.

Palin was a disaster becasue she wasn't ready for the spotlight and nobody could imagine her being a heartbeat away from the presidency. Ryan has yet to be scrutinized in interviews (and he probably won't due to our pathetic media). But, with his clear lack of foreign policy creditibility along with "Romney Shambles" - the same problem could emerge with Ryan on the ticket. They both need to be pressed on foreign policy and the debate where that is suppose to be the central focus should be very harmful for both R&R.

2. Ryan has a very thin resume. No real world experience beyond brief stints driving an Oscar Mayer

Weinermobile and flipping burgers at McDonald's. He's been a congressional politician or worked for politicians his whole life. His experience as a politician is narrowly focused on his Randian centric "budget" (known in earlier years as the roadmap). That's it.
Not a Senator or Governor, never a cabinet member, not an academic, no military service, no managerial or commercial experience, no foreign service,... Not presidential material.